RPS6KB1 and breast cancer: Recurrent fusions involving VMP1 as 3ʹ fusion partner have previously been reported with ribosomal protein S6 kinase B1 (RPS6KB1) in breast tumors37, in the HER2-amplified breast cancer cell line BT-47438, in esophageal adenocarcinoma39, as well as in MCF7 breast cancer cells40, 41.